Abstract: A scalable network architecture adapted to interface with various sensor types and sensor access mechanisms while providing real-time access to sensor data for distributed applications and organizations is described. A centralized sensor network service manages the registration, capabilities, near real-time status of the sensors and their current network connections. New sensors are discovered automatically through messaging between network access nodes and the sensor registry. The registry service can be made available to distributed sensor applications and sensor middleware, and facilitates the sharing of sensors across organizations. The sensor registry is automatically updated by network software and does not require manual configuration or reconfiguration each time a sensor is added to or relocated within the network. Authentication and authorization policies can be implemented to ensure that only authorized applications can query and view the registry.

Abstract: Described is a method for reliable transmission of sensor data and sensor commands. The method is particularly useful for shared packet networks and lossy wireless networks where the rate of packet drops can be significant. A network access node receives a data packet that includes the sensor data and multicasts the data packet towards an aggregation node. Each data packet preferably is transmitted over a unique network path. The number of multicast data packets is determined according to one or more network parameters such as network congestion, packet drop probability, the priority and class of service of the data packet, and the number of unique network paths between the network access node and an aggregation node. The first data packet to arrive at the aggregation node is forwarded to the application node and subsequently received data packets with identical sensor data are discarded.